Generally, a railroad operating company manages train operations by inputting data such as departure times of trains at each station and distances (kilometers) between neighboring stations on a diagram creating device, and creating diagram data, and then displaying this diagram data on a screen as an operation diagram (referred to as a “diagram” below.). For example, the diagram adopts a kilometer from a departure station (reference station) for a vertical axis and a time for a horizontal axis, and is expressed as a graph in which a traveling station name is arranged on the vertical axis taking an inter-station distance into account.
Further, one train is expressed by one line (diagram line) on the diagram. If a departure station of an outbound train is arranged at the top and coordinates axes are arranged such that the kilometer increases downward and the time increases rightward based on the departure station as the origin, while the outbound train draws a line going downward to the right, an inbound train draws a polygonal line going upward to the right. An inclination of a polygonal line represents a speed of a train. When the speed of a train is faster, the inclination of the line is greater. A horizontal line (inclination 0) indicates that the train stops.
Further, when an operation diagram in a railroad network having track sections including multiple junctions is created, a device to draw junction destination track sections in one screen is made.
The following literature relates to the above technique, the entire content of which are incorporated herein by reference.